title: [Three-dimensional thickness and volume measurements of the knee joint cartilage by MR tomography: reproducibility in volunteers].
abstract: OBJECTIVE
  To determine the reproducibility of three-dimensional volume and thickness measurements of the knee joint cartilage with MRI in volunteers.
  
  
  METHODS
  The knees of 7 healthy individuals (ages 23 to 58 yrs.) were sagittally imaged with a resolution of 2 x 0.31 x 0.31 mm3, using a fat-suppressed FLASH-3 D sequence. The knee was repositioned in between replicate acquisitions, 6 data sets being obtained in each case. After semiautomatic segmentation and three-dimensional reconstruction of the cartilage, the thickness was determined independent of the original section orientation. The coefficient of variation for repeated volume measurements and the deviations of the maximal cartilage thickness values were calculated subsequently.
  
  
  RESULTS
  The mean variation of the cartilage volumes of the replicate measurements was 1.4% (+/- 0.8%) in the patella, 1.7% (+/- 1.5%) in the femur, 3.0% (+/- 1.2%) in the medial tibial plateau and 3.5% (+/- 2.0%) in the lateral tibial plateau. The comparison of the distribution patterns of cartilage thickness yielded a high degree of agreement. Only in rare cases deviations of more than 0.5 mm were observed.
  
  
  CONCLUSIONS
  The results show that the presented method for determining the quantitative distribution of articular cartilage yields a high degree of precision. It offers new possibilities in screening risk groups, monitoring the course of degenerative joint disease and the investigation of functional adaptation of the cartilage to mechanical loading.
authors.affiliation: Institut für Radiologische Diagnostik, Klinikum Grosshadern, München.
authors.forename: J
authors.initials: J
authors.lastname: Westhoff
authors.forename: F
authors.initials: F
authors.lastname: Eckstein
authors.forename: H
authors.initials: H
authors.lastname: Sittek
authors.forename: A
authors.initials: A
authors.lastname: Lösch
authors.forename: S
authors.initials: S
authors.lastname: Faber
authors.forename: H
authors.initials: H
authors.lastname: Kolem
authors.forename: K H
authors.initials: KH
authors.lastname: Englmeier
authors.forename: M
authors.initials: M
authors.lastname: Reiser
mesh_terms: D000328:Adult; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D005260:Female; D005269:Femur / Q000033:anatomy & histology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010329:Patella / Q000033:anatomy & histology; D015203:Reproducibility of Results; D013977:Tibia / Q000033:anatomy & histology
vernacular_title: Dreidimensionale Dicken- und Volumenbestimmung des Kniegelenkknorpels mit der MRT: Reproduzierbarkeit am Probanden.